1. Field of the Invention
The present invention relates to a system for interconnecting batteries and more particularly to apparatus for jumping automobile batteries to start an automobile or charge a discharged battery.
The type of batteries normally found in automobiles are lead-acid type that generate gases which, if ignited, can explode resulting in considerable damage or injury.
A usual situation in which there is danger of an exploding battery is when an automobile battery has been discharged and it is determined to jump start the car with a battery in another car. In such situations as the cables between the charged battery and the discharged battery are being connected sparks can occur and these sparks can result in ignition of the battery gases. Conventionally, automobile battery jumper cables carry a tag in which instructions are written on the proper method and sequence of connecting the cables. Nevertheless, situations can occur when the instructions are not properly followed or through misinterpretation or otherwise and a spark occurs. A battery can be damaged if charged at too high a rate. An undamaged battery will allow the proper rate of charge from another undamaged battery, but if one battery has developed an internal short circuit within one of its cells, an unusually high rate of current could pass causing aggravated damage and possible an explosion.
It is to this general problem that the present invention is directed.
2. Description of the Prior Art
The prior art has recognized the above discussed problem and various types of jumper cables have been designed in an attempt to insure proper connection of the cables and elimination of the possibility of gas igniting sparks. Representative of the prior art is U.S. Pat. No. 4,166,241 in which there is a relay switch to maintain one of the cables in an open circuit condition while the connections are being made and also appropriate indicating lamps to indicate to the operator that the cables are correctly connected to the two batteries in regard to their polarity.
Although some of these patents may decrease the possibility of sparks and resulting fire or explosion, they do not eliminate such dangers.